RU2541956C1 - Single kochetov's acoustic absorber of combined type - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: in single acoustic absorber of combined type containing active and reactive acoustic absorbers located on rigid framework, the framework is made out of two parts. The bottom part is made in form of a rigid, hollow structure of cylindrical-and-cone shape, and top part is made in form of rigid perforated cylindrical shell with perforated cover and solid base. Cavity of the cylindrical shell is filled with sound absorbing material, and connection between top and bottom parts is made by means of the resilient damping element ensuring damping of HF oscillations. On the perforated cover of the perforated cylindrical shell the pin connected element is installed to secure the framework to the required object. Around the perforated cylindrical shell there is spiral sound absorbing element. In the framework bottom part the hollow cylindrical part of the framework is made as resonance Helmholtz muffler and contains mouths of different diameters located on the cover and base of the hollow cylinder, and on its side surface, at that the hollow cone and cylindrical parts are connected by the mouth.

EFFECT: improved efficiency of noise suppression at high frequencies.

2 cl, 1 dwg

Description

The invention relates to noise reduction in industrial and transport facilities.

Known designs of piece sound absorbers made in the form of volumetric parallelepipeds, cubic, conical, the cavities of which are filled with sound-absorbing material [1, 2, 3, 4]. Currently, fibrous sound absorbers are the most common in construction practice.

The disadvantages of the known piece sound absorbers are the relatively low efficiency at low and medium frequencies, and they do not meet the increased requirements for room design.

Known conical piece sound absorber according to the patent of the Russian Federation No. 22822004 [5], consisting of a rigid frame suspended by hooks on cables to the ceiling of the industrial building with sound-absorbing material located inside the frame wrapped with mesh nylon fabric, the frame is made in the form of a cone attached to it the lower flange with a hemisphere also containing sound-absorbing material wrapped in a mesh nylon fabric or fiberglass, and filling with sound-absorbing material can be as with air cavities and located on the periphery of the hemisphere, as well as within it in a checkerboard pattern on the three coordinate planes.

Its disadvantage is the relatively low efficiency of sound attenuation at high frequencies due to the lack of sound-reflecting layers that perform sound insulation functions at high frequencies.

Known cylindrical resonant piece sound absorber according to the patent of the Russian Federation No. 23033679 [6], consisting of a rigid frame suspended by hooks on cables to the ceiling of the industrial building with a sound-absorbing material located inside the frame wrapped in a mesh nylon fabric, the frame is made cylindrical in the form of a perforated round glass and lids, inside of which is located a central rod rigidly fixed to the axis of the glass, on which round partitions are mounted with the possibility of their fixation, inside one of which is a sound-absorbing material wrapped in a mesh nylon fabric.

The disadvantage is the relatively low noise attenuation efficiency at low frequencies due to the cramped dimensions for placing resonant cameras.

Known cubic piece sound absorber according to the patent of the Russian Federation No. 2334062 [7], consisting of a rigid frame suspended by hooks on cables to the ceiling of the industrial building with a sound-absorbing material located inside the frame wrapped with mesh nylon fabric, the frame is made in the form of two cubic surfaces, one of which - external - is perforated, and the other - internal - is acoustically transparent, and the sound-absorbing material wrapped in a mesh nylon fabric is located in the gap between the frame s, which are interconnected by means of resonance inserts of different diameters, and the inner cavity is divided by a partition into two resonant cavities, one of which is filled with a sound absorber.

The disadvantage is the relatively low efficiency of sound attenuation at high frequencies due to the lack of sound-reflecting layers that perform the functions of sound insulation at high frequencies.

Volumetric piece sound absorbers are known according to the patents of the Russian Federation No. 2354786 [8] and the Russian Federation No. 2485256 [9], consisting of a rigid frame suspended on a fastener to the ceiling of the industrial building, the frame is made with sound-absorbing material wrapped in an acoustically transparent material.

Their disadvantage is the relatively low noise attenuation efficiency at high frequencies due to the lack of Helmholtz resonators.

The closest technical solution to the technical nature and the achieved result is a piece sound absorber according to the patent of the Russian Federation No. 2495202 [10], containing a rigid perforated frame, inside which a sound-absorbing material is placed, the frame is made of the lower part of the conical shape with a cover and the upper part of the cylindrical shape, which is attached to the cover of the lower part of the perforated frame by means of a vibration damping pad, which allows damping high-frequency vibrations, while to the upper part is cylindrical about the perforated frame, the element is pivotally fixed by means of which the frame is attached to the desired object, for example, the ceiling of the production room, and the cavities of the lower and upper parts of the perforated frame are filled with sound-absorbing materials of different densities, and at least one sound-absorbing screw is located around the upper part of the cylindrical shape of the perforated frame piece absorber element made in the form of a cylindrical coil spring from a dense non-combustible sound-absorbing about the material.

The disadvantage of this piece sound absorber is the relatively low noise reduction efficiency at low and medium frequencies due to the lack of volume cavities for Helmholtz resonators and cavities filled with a sound absorber, i.e. absorbers of various densities.

EFFECT: increased efficiency of sound attenuation at high frequencies by introducing volume cavities for Helmholtz resonators into a piece sound absorber, which increase efficiency at high frequencies.

This is achieved by the fact that in a piece sound absorber of a combined type containing active and reactive sound absorbers placed on a rigid frame, the frame is made of two parts, while the lower, reactive part is made in the form of a rigid, hollow cylindrical-conical structure, and the upper, active , the part is made in the form of a rigid perforated cylindrical shell with a perforated cover and a solid base, and the cavity of the cylindrical shell is filled with sound-absorbing material, and the connection is vertical the heel and the lower parts are made by means of an elastic damping element that allows damping high-frequency vibrations, while the element is pivotally fixed to the perforated cover of the perforated cylindrical shell, by which the frame is attached to the desired object, for example, the ceiling of the production room, while at least around the perforated cylindrical shell one screw sound-absorbing element.

The drawing shows a diagram of a piece sound absorber of a combined type.

A combined type of sound absorber contains a rigid frame, which is made of two parts, the lower 1, reactive, part made in the form of a rigid, hollow cylinder-shaped structure, and the upper 14, active, part made in the form of a rigid perforated cylindrical shell 12 with a perforated cover and a solid base, and the cavity of the cylindrical shell is filled with sound-absorbing material. The connection of the upper 14 and lower 1 parts is made by means of an elastic damping element 13, which allows damping high-frequency vibrations, while an element is pivotally fixed to the perforated cover of the perforated cylindrical shell, by which the frame is attached to the desired object, for example, the ceiling of the production room.

Around the perforated cylindrical shell 12 is located at least one screw sound-absorbing element 15, made in the form of a cylindrical helical spring, covering the shell 12.

In the lower 1, reactive part of the frame, the cylindrical part 2 is hollow in the form of a Helmholtz resonant silencer with resonator necks 5, 6, 7 of different diameters located in the cover 4 and base 3 of the hollow cylinder, as well as on its side surface, and the cavity of the conical part 11 is a Helmholtz resonator with a neck 6 located in the base 3 of the cylinder.

The screw sound-absorbing element 15 is made in the form of a hollow screw sound-absorbing element formed by the external and internal screw surfaces forming a cavity (not shown in the drawing), while the space formed by the external and internal screw surfaces is filled with sound-absorbing material (not shown in the drawing) with a density less than the screw sound absorbing element 15.

The inner walls of the hollow skeleton of a cylindrical-conical shape are made rigid, for example, in the conical part 11, surface 9, and the outer 8 are perforated, and the space between them is filled with sound absorber 10.

A unit sound absorber of a combined type operates as follows.

Sound waves propagating in industrial or transport facilities interact with sound-absorbing material 10 located in the lower 1 part of the frame, as well as in a perforated cylindrical shell 12 and a screw sound-absorbing element 15 of the upper 14 parts, which suppress noise in different frequency bands, for example, at low and mid frequencies respectively.

The connection of the upper 14 and lower 1 parts by means of an elastic damping element 13 allows you to damp high-frequency vibrations that can be emitted by a rigid frame, which allows it to be used to reduce noise on transport objects.

Sound absorption at medium and high frequencies occurs due to the acoustic effect built on the principle of Helmholtz resonators formed by air cavities of a perforated frame. In the lower 1, reactive, part of the frame, the cylindrical part 2 is hollow in the form of a Helmholtz resonant silencer with the neck of the resonator 5, 6, 7 of different diameters, with different volumes of the resonant cavities in the lower part of the conical shape - cavity 11, and in the cylindrical - cavity 2 , serve to suppress sound vibrations in the required sound frequency range, as a rule, large volumes for noise suppression in the low-frequency range, and small ones in the medium and high frequencies. The interaction of sound waves with a screw sound-absorbing element 15 leads to noise attenuation in the high frequency range, and the implementation of a sound absorber from non-combustible materials makes the design fireproof.

Information sources

1. Kochetov O.S., Sazhin B.S. Noise and vibration reduction in production: theory, calculation, technical solutions. M .: MSTU im. A.N. Kosygina, 2001 .-- 319 p. (Fig. P. Sh10, p. 263).

2. Kochetov O.S. Textile vibroacoustics. Textbook for universities. M .: MSTU im. A.N. Kosygina, the group "Sovezh Bevo", 2003. - 191 p. (Fig. A.2, p. 176).

3. Kochetov OS Laboratory workshop on industrial sanitation. Textbook for universities. M .: MSTU im. A.N. Kosygina, “Sovezh Bevo” group, 2004. - 168 p. (Fig.6.6, p. 120).

4.Kochetov O.S. Sound-absorbing structures to reduce noise in the workplace of industrial premises. The journal "Labor safety in industry", No. 11, 2010, pp. 46-50 (Fig. 1; p. 48, and Fig. 2; p. 48).

5.Kochetov O.S., Kochetova M.O., Khodakova T.D., Elin A.M. Conical piece sound absorber // Patent for invention No. 2282004. Published on August 20, 2006. Bulletin of inventions No. 23.

6. Kochetov O.S., Kochetova M.O., Khodakova T.D. Cylindrical resonant piece sound absorber // Patent for invention No. 2303679. Published on July 27th, 2007. Bulletin of inventions No. 21.

7. Kochetov O.S., Kochetova M.O., Khodakova T.D. Cubic piece sound absorber // Patent for invention No. 2334062. Published on September 20, 2008. Bulletin of inventions No. 26.

8.Kochetov O.S., Kochetova M.O., Kochetov S.S., Kochetov Sergey Sergeevich. Volumetric piece sound absorber // Patent for invention No. 2354786. Published on May 10th, 2009. Bulletin of inventions No. 13.

9. Kochetov O.S. Piece sound absorber // Patent for invention No. 2485256. Published 06/20/2013. Bulletin of inventions No. 17.

10. Kochetov O.S., Stareeva M.O. Piece sound absorber // RF patent for the invention No. 2495202. Published 10/10/2013. Bulletin of inventions No. 28.

Claims (2)

1. A combined type sound absorber containing active and reactive sound absorbers placed on a rigid frame, the frame is made of two parts, while the lower, reactive part is made in the form of a rigid, hollow cylinder-conical structure, and the upper, active part is made in in the form of a rigid perforated cylindrical shell with a perforated lid and a solid base, and the cavity of the cylindrical shell is filled with sound-absorbing material, and the connection of the upper and lower parts flaxen by means of an elastic damping element that allows you to damp high-frequency vibrations, while the element is pivotally fixed to the perforated cover of the perforated cylindrical shell, by means of which the frame is attached to the desired object, for example, the ceiling of the production room, while at least one screw sound-absorbing element is located around the perforated cylindrical shell made in the form of a cylindrical coil spring, covering the shell, characterized in that the bottom To it, the reactive part of the frame, the cylindrical part is hollow in the form of a Helmholtz resonant silencer with resonator mouths of different diameters located in the lid and base of the hollow cylinder, as well as on its side surface, and the cavity of the conical part is a Helmholtz resonator with a neck located in the base cylinder. 2. The combined type sound absorber according to claim 1, characterized in that the screw sound-absorbing element is made in the form of a hollow screw sound-absorbing element formed by external and internal screw surfaces forming a cavity, while the space formed by the external and internal screw surfaces is filled with sound-absorbing material with a density lower than that of a screw sound-absorbing element.

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